docs: def get_kkf(ekey):
      """
      :param ekey: export key, for instance ('uhs/rlz-1', 'xml')
      :returns: key, kind and fmt from the export key, i.e. 'uhs', 'rlz-1', 'xml'
      """
      key, fmt = ekey
      if '/' in key:
          key, kind = key.split('/', 1)
      else:
          kind = ''
      return key, kind, fmt